In threaded piping systems, selecting the right fitting is essential for system safety, efficiency, and long-term reliability. Among malleable iron threaded fittings, FIG 220 and FIG 270 are two commonly specified socket types that often cause confusion for buyers, engineers, and contractors.

Although they may appear similar at first glance, FIG 220 and FIG 270 threaded sockets are designed for different connection purposes and application scenarios. This article provides a clear comparison to help you understand their differences and choose the correct option for your project.

Overview of FIG 220 and FIG 270 Threaded Sockets

What Is a FIG 220 Socket Part Threaded?

A FIG 220 socket part threaded is a straight threaded socket with internal threads on both ends. It is used to connect two pipes of the same nominal diameter in a straight line.

FIG 220 sockets are widely applied in:

• Water supply pipelines

• Gas distribution systems

• HVAC installations

• Industrial fluid transfer systems

They are typically manufactured from malleable iron and produced according to standards such as EN 10242 and ASME B16.3.

What Is a FIG 270 Reducing Socket?

A FIG 270 socket, often referred to as a reducing socket, is designed to connect two pipes of different diameters. One end has a larger internal thread, while the other has a smaller internal thread.

FIG 270 fittings are commonly used when:

• A pipeline needs to transition between different pipe sizes

• Space is limited and reducers must be compact

• System design requires flexible size adaptation

  
  

Key Differences Between FIG 220 and FIG 270

Understanding the functional differences between these two fittings is critical when specifying materials or placing procurement orders.

1. Connection Function

• FIG 220: Connects pipes of the same size

• FIG 270: Connects pipes of different sizes

If your system requires a straight, uniform pipeline, FIG 220 is the correct choice. If a size transition is required, FIG 270 is necessary.

2. Dimensional Structure

• FIG 220 sockets are symmetrical, with identical thread sizes on both ends

• FIG 270 sockets have an asymmetrical design with different thread diameters

This structural difference directly affects flow characteristics, pressure distribution, and installation layout.

3. Application Scenarios

Standards and Thread Types

Both FIG 220 and FIG 270 threaded sockets are typically produced in accordance with internationally recognized standards, including:

• EN 10242

• ASME B16.3

• ISO 49

They are available with:

• BSP threads (commonly used in Europe, Asia, Middle East)

• NPT threads (commonly used in North America)

Reliable manufacturers such as KOXY ensure strict compliance with these standards, providing accurate threads, consistent dimensions, and dependable sealing performance.

Material and Surface Finish Comparison

Both FIG 220 and FIG 270 fittings are commonly made from malleable iron, which offers:

• High tensile strength

• Good ductility

• Resistance to cracking under pressure

Typical surface finishes include:

• Black (oil-coated) for indoor or dry environments

• Hot-dip galvanized for enhanced corrosion resistance in outdoor or humid conditions

When selecting between FIG 220 and FIG 270, the material and coating options are usually the same—the key difference lies in their functional design, not their material quality.

Pressure and Temperature Performance

Both fittings are designed to handle similar operating conditions:

• Pressure rating: PN16–PN25 or Class 150 (depending on size and standard)

• Working temperature: Up to approximately 200°C

However, engineers should note that reducing fittings like FIG 270 may introduce localized flow changes. Proper system design is essential to avoid unnecessary pressure loss.

How to Choose the Right Threaded Socket

When deciding between FIG 220 and FIG 270, consider the following questions:

1. Are the two connecting pipes the same size?

• Yes → Choose FIG 220

• No → Choose FIG 270




2. Does the system require future disassembly or maintenance?

• FIG 220 is often preferred for straight, serviceable connections

  
  

3. Is space limited in the pipeline layout?

• FIG 270 can provide a compact size transition solution

  
  

Procurement teams should also verify thread type (BSP or NPT), pressure requirements, and coating specifications before placing an order.

Why Supplier Selection Matters

Even when the correct fitting type is selected, overall system performance depends heavily on manufacturing quality. Poor thread accuracy or inconsistent dimensions can lead to leaks, installation delays, and long-term maintenance issues.

As an experienced manufacturer and exporter of threaded pipe fittings, KOXY supplies both FIG 220 and FIG 270 sockets with:

• Strict dimensional control

• Verified material quality

• Compliance with international standards

• Stable supply for construction and industrial projects

This makes KOXY a reliable partner for distributors, contractors, and engineering firms seeking consistent performance and dependable delivery.

Conclusion

While FIG 220 and FIG 270 threaded sockets may look similar, they serve distinct purposes in piping systems. FIG 220 is designed for straight connections between pipes of the same size, while FIG 270 enables smooth transitions between different pipe diameters.

Understanding these differences helps engineers, builders, and procurement professionals avoid costly mistakes and ensure system reliability. By selecting the appropriate fitting and sourcing it from a trusted supplier like KOXY, you can achieve safer installations, smoother operations, and long-term performance across a wide range of applications.